With new bitbake UIs having the cooker exit at 'random' points
in the codebase is problematic. This patch raises an exception
which matches the siutation instead.
(Bitbake rev: a50017ba71250e1710a6425b60ac7e3f03d88295)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>